Gamma Oryzanol
Gamma oryzanol is a multi-functional phytosterol from rice bran oil with powerful antioxidant and anti-inflammatory abilities.1 It contains a mixture of sterols and ferulic acids that effectively combat free radicals and UV damage while slowing the progress of melanin pigmentation in the skin.2 Oryzanol can also stabalise oils from oxidation and moisturise dry skin by stimulating the sebaceous glands to balance natural oil production.3
Oryzanol inhibits melanin synthesis in two ways: by inhibiting tyrosinase enzyme activity and by reducing the expression of microphthalmia-associated transcription factor (MITF).2 MITF controls the expression of various genes that are essential for melanin synthesis in melanocytes, so suppressing it results in a lightened skin tone.4
references
[1] Saenjum, Chalermpong & Chaiyasut, Chaiyavat & Chansakaow, Sunee & Suttajit, Maitree & Sirithunyalug, Busaban. (2012). Antioxidant and anti-inflammatory activities of gamma-oryzanol rich extracts from Thai purple rice bran. Journal of Medicinal Plants Research. 6.
[2] Jun H., Lee J., Cho B., Seo W., Kang H., Kim D., Cho K., and Lee. (2012), Dual Inhibition of γ-Oryzanol on Cellular Melanogenesis: Inhibition of Tyrosinase Activity and Reduction of Melanogenic Gene Expression by a Protein Kinase A-Dependent Mechanism. J. Nat. Prod. 75, 10, 1706-1711. doi:10.1021/np300250m
[3] Ueda, H., Hayakawa, R., Hoshino, S. and Kobayashi, M. (1976), THE EFFECT OF TOPICALLY APPLIED γ‐ORYZANOL ON SEBACEOUS GLANDS. The Journal of Dermatology, 3: 19-24. doi:10.1111/j.1346-8138.1976.tb00965.x
[4] Wikipedia contributors. (2019, December 18). Microphthalmia-associated transcription factor. In Wikipedia, The Free Encyclopedia. Retrieved 01:02, January 23, 2020, from https://en.wikipedia.org/w/index.php?title=Microphthalmia-associated_transcription_factor&oldid=931290860